Method of prevention of dust explosions and fires in mills and elevators



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L. A. STINSON METHOD OF PREVENTION OF DUST EXPLOSIONS AND FIRES IN MILLSAND ELEVATORS Filed Dec. 51

OR 1 q 6 1 2 9072' Dec. 28 1926.

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Patented Dec. 28, 1926.

LEWIS ANDREW STIN'SON, OF O-A'K PARK, ILLINOIS.

METHOD OF PREVENTION OF DUST EXPLOSIONS AND FIRES IN MILLS ANDELEVATORS.

Application filed December 31, 1924. Serial No. 759,194.

My invention relates to a method of dusting and sweeping mills andelevators and similar buildings and at the same time rendering the dustand sweepings noncombustible so that regardless of how much dust theremay be produced in the atmosphere by reason of the dusting and sweepingthe very act of dislodging this dust renders it inexplosive andnoncombustible.

It is well known that dust explosions are frequent and that dreadfulexplosions and fires have resulted from the dust igniting in mills andelevators.

These explosions frequently take place while there is dusting andsweeping going on, so that the very act of cleaning up the dust is ahazardous matter, because the dust which is swept and brushed downfloats in the atmosphere to the point of saturation where a spark fromany source ignites it in the well known manner that causes explosions.

At other times a sudden shock or jar dislodges dust that becomes ignitedfrom various causes. In the normal service of the machinery in such amill dust accumulates in the air to the point where it becomes explosiveand gets ignited by various accidental means.

It is substantially impossible to always keep all the dust sufficientlycleaned up in the flour mills and elevators to insure complete safetyagainst dust explosions, and the best method that is known to me is toprovide a means of cleaning up or removing the dust in a manner thatwill make the dust inexplosive and noncombustible really before it isdislodged from any place of rest.

I accomplish this result by my method herein set forth.

Reference-will be had to the accompanying drawing which isdiagrammatical only and involves a nozzle adapted to spray a liquid andas occasion requires a. blast of air along therewith, that will dislodgeand blow down the dust from walls, machinery and other places oflodgment by the force and the pipe to a source of supply of compressedair and a source of supply under pressure of the liquid to be sprayed.

2 indicates the nozzle, and 3 the supply pipe connected therewith whichreceives its supply of compressed air by a hose connection t, connectedto any suitable supply of compressed air.

5 indicates the hose connected to any suitable supply of fire proofingsolution under pressure. 6 indicates the wall which is being sprayed ordusted by the spray and air nozzle as described.

In localities or places wherein the dust accumulates rapidly andparticularly in dangerous places such as around drying machines or inheads, boots and spouts that require cleaning frequently and in placesnot convenient for an operator to reach with a hand-controlled nozzle, Iwill provide fixed piping and fixed spray nozzles under the control ofsuitable valves to be dusted out and protected by an operator as oftenas oc casion may require.

A relatively small percentage of a fire proofing solution when applieddirectly as a means of dislodging the dust renders the dust inexplosiveand at the same time fire proof when this dust becomes accumulated inany sort of a mass on the floor or other spaces.

The solution that I prefer to use for this purpose measured in units ofabout 35 gallons is substantially, sulphuric acid chemically pure, 1quart, 6 pounds of bicarbonate of soda, mixed and dissolved in 35gallons of water.

The method-0f mixing is to put the acid and water together first andstir the soda in at the last.

Other solutions besides this may be used but this solution is foundsatisfactory. The solution spray alone or volume of air which is sprayedalong with this solution is sufli- 100 cient, together with the force ofthe spray, to dislodge and blow the dust away from crevices in the wallsand machinery and other places, and thus saturated with the waterysolution the material falls to the floor 105 and is swept up and removedas a harmless inert material from the standpoint of explosions andfires.

The amount of solution that is mixed in this dust is not sufficient todiminish the volved is desirable for that purpose, nor is the quantityof the solution sufioient to damage the dust thus treated to the pointof injuring its storage or keeping qualities.

More dust explosions are caused in the very act of dusting and brushingdown and cleaning up the premises than are caused by all other agencies,and by my method of doing the dusting work the possibility of explosionis entirely eliminated.

What I claim is:

1. A method of preventing dust explosions, which involves thedislo-dging of the dust with the assistance of a spray containing achemical which renders the dust inexplosive.

2. A method of dislodging dust which con sists in spraying the same bymeans of an air blast in conjunction with a spray having incorporatedtherewith a fireproofing in-- 20 gredient adapted to render the dustinexplosive.

3. A method of preventing fires and dust explosions which consists inspraying the dust areas with a solution of a fire preven- 2 tionmaterial during the act of dislodging the dust.

4. A method of preventing fires and explosions in mills and elevatorswhich consists in spraying into the field of the dust a solu- 30 tion ofa fire prevention material combined with an air blast adapted todislodge the dust.

Signed at Chicago, in the county of Cook, and State of Illinois, this26th day of De- 35 cember, 1924.

LEWIS ANDREW STINSON.

